MIRCEA RIVIS, MARIUS PRICOP, S. TALPOS, ROBERT CIOCOIU, IULIAN ANTONIAC, DANIELA GHEORGHITA, OCTAVIAN TRANTE, HORATIU MOLDOVAN, GABRIEL GRIGORESCU, VICENTIU SECELEANU, AUREL MOHAN, SERBAN TALPOS NICULESCUINFLUENCE OF THE BONE CEMENTS PROCESSING ON THE MECHANICAL PROPERTIES IN CRANIOPLASTY The aim of this study is to observe the time of mixing influence on the properties of commercially available PMMA bone cement, widely used in cranioplasty. The studied bone cement is provided in the form of a solid powder (the copolymer) and a liquid monomer. The increase of the mixing phase duration and the use of two mixing methods (manual and mechanical) effect on surface and mechanical characteristics were studied. The samples were prepared as if in the operation room. Surface characteristics were studied by means of contact angle measurements, morphology by scanning electron microscopy (SEM) and mechanical characteristics determined by flexural tests in a three point bending configuration. The conclusion of this study is that by using a mechanical mixing method and increasing mixing time higher flexural strength can be achieved by reducing pore content within bone cement.